Gender-dimorphic regulation of muscular proteins in response to high fat diet and sex steroid hormones

A novel PNPLA2 mutation causing total loss of RNA and protein expression in two NLSDM siblings with early onset but slowly progressive severe myopathy

Neutral lipid storage disease with myopathy (NLSDM) is a rare autosomal recessive disorder, due to an enzymatic error of lipid metabolism. Patients present always with skeletal muscle myopathy and variable cardiac and hepatic involvement. NLSDM is caused by mutations in the PNPLA2 gene, which encodes the adipose triglyceride lipase (ATGL). Here we report the molecular characterization and clinical findings of two NLSDM siblings carrying the novel c.187+1G > C homozygous PNPLA2 mutation, localized in the splice site of intron 2. Molecular analyses revealed that neither aberrant PNPLA2 mRNA isoforms, nor ATGL mutated protein were detectable in patient's cells. Clinically, both patients presented early onset muscle weakness, in particular of proximal upper limb muscles. In almost 15 years, muscle damage affected also distal upper limbs. This is a NLSDM family, displaying a severe PNPLA2 mutation in two siblings with clinical presentation characterized by an early onset, but a slowly evolution of severe myopathy.

A 7-day high-PUFA diet reduces angiopoietin-like protein 3 and 8 responses and postprandial triglyceride levels in healthy females but not males: a randomized control trial

BACKGROUND

Polyunsaturated fatty acids (PUFAs) have beneficial effects on hypertriglyceridemia although their effect on angiopoietin-like proteins (ANGPTLs), specifically ANGPTL3, ANGPTL4 and ANGPTL8 is unknown.

OBJECTIVE

To determine whether a high-PUFA diet improves postprandial triglyceride (TG) levels through reducing ANGPTL responses following high saturated fat (SFA) meals.

METHODS

Twenty-six adults were randomized into a PUFA diet (n = 16) or a control diet group (n = 10). Participants completed a pre-diet visit (v1) where they were given two SFA-rich, high-fat meals. Blood draws were taken at fasting and every 2 h postprandially for a total of 8 h. After v1, participants completed a 7d diet of the same macronutrient proportions (50% carbohydrate, 35% fat, 15% protein) but with different fatty acid (FA) compositions (PUFA = 21% of total energy from PUFAs vs. Control = 7% of total energy from PUFA). All participants then completed the post-diet visit (v2) identical to v1.

RESULTS

In the PUFA group, females, but not males, reduced TG concentrations (Area under the curve (AUC): 141.2 ± 18.7 vs. 80.7 ± 6.5 mg/dL/h, p = 0.01, for v1 vs. v2, respectively). Fasting and postprandial AUC levels of ANGPTL3 and 8, but not ANGPTL4, also decreased from v1 to v2 in PUFA females, but not males. No changes from v1 to v2 were seen in either sex in the control group.

CONCLUSIONS

A PUFA-rich diet improves TG levels in response to high-SFA meals with reductions in ANGPTL3 and ANGPTL8. PUFAs may be more protective against hypertriglyceridemia in females, compared to males since no diet effect was observed in males.

TRIAL REGISTRATION

NCT02246933.